DE1298091B - Process for the preparation of mixtures of phosphoric acid esters - Google Patents

Description

The invention relates to a process for the production of new phosphoric acid esters, in the case of white phosphorus, air or oxygen and an alcohol directly with one another implemented.

The new phosphoric acid esters obtained according to the invention can be used as surface-active agents, emulsifiers, flotation agents, lubricant additives, Fuel additives, corrosion inhibitors, metal complexing agents and the like.

It is known that by reacting white phosphorus with a saturated alkanol and oxygen in low yields dialkyl phosphites under certain conditions, such as temperatures between 40 and 75C and excess alcohol, can get. However, there is no known process with which one can by direct implementation such components can produce esters of the following type.

The new process involves the preparation of a mixture of esters of mixed acids of phosphorus, where phosphorus is statistically the oxidation state 4 has. The mixture mainly contains monoalkyl phosphites, mono- and dialkyl phosphates, Alkyl pyrophosphates and alkyl hypophosphates. The reaction products can also be used as Alcoholysis and hydrolysis products of a previously unknown substance, namely des Hypophosphorous acid anhydride Po08.

The invention relates to a process for the preparation of mixtures of phosphoric acid esters, in which the statistically calculated oxidation level des Phosphorus is between 3.5 and 4.5, which is characterized in that one Alcohol with white phosphorus and oxygen or a gas containing oxygen in the presence of an inert solvent at temperatures between 0 and 45 ° C implements.

When the upper limit of the specified temperature range is exceeded unwanted by-products such as dialkyl phosphites are formed in varying amounts and other undesirable organophosphorus compounds.

The reaction is preferably allowed to take place at temperatures from 25 to 35.degree expire and, if necessary, maintains this temperature during the reaction period upright through external cooling.

Such inert solvents can be used in which both the alcoholic reaction component and the reaction products are soluble and in which white phosphorus and oxygen are at least somewhat soluble. the Solvents should not change during the reaction and afterwards to the essential Part can be recovered.

These conditions are used by lower alkyl esters such as ethyl acetate and butyl acetate, satisfactorily met.

Ethyl acetate is preferably to be used because of its proportion low price and low boiling point, which makes solvent removal relieved after the reaction has ended.

The course of the reaction can be determined by the amount of air or. Oxygen supply are controlled or controlled in the reaction mixture. The other reaction components can be mixed together at the beginning of the reaction, or they can be mixed during be added gradually to the reaction. A suspension is preferably used first of the phosphorus produced in the inert solvent, the alcohol during the reaction added and the course of the reaction or the reaction rate by regulation the air or oxygen supply controlled.

The preferred ratio of reactants is -1 gram atom Phosphorus to 1 mole of the alcohol, which is how long it reacts with air or oxygen leaves until the phosphorus has essentially reacted. With this ratio of Reaction components are obtained as a mixture of compounds, which is statistically the Composition of dialkyl dihydrogen hypophosphates corresponds, in particular with regard to the relevant oxidation level of phosphorus, the acid number and the ratio from alkyl to phosphorus.

The reaction products of this process and those of the implementation These products with bases or alkylene oxides are for different products Purposes usable e.g. B. as emulsifiers, surface-active agents, flotation agents, Corrosion protection agents, fuel additives, lubricant additives, metal complexing agents and metal extractants. For most purposes, such esters are preferable in which the organic radicals contain 6 or more carbon atoms.

Example 1 A reaction vessel was used which was equipped with a effective stirrer, a dropping funnel, a thermometer, a feed tube for Air and a reflux condenser was provided. The exit of the reflux condenser was with a glass tube over an empty 10 l bottle with an effective, with dry ice and acetone cooled cold trap connected. Funding was provided to support the in the amount of air flowing into the reaction vessel and the amount of air emerging from the cold trap Measure the amount of gas.

In the reaction vessel 300 g of ethyl acetate were precipitated and then under 40 g of molten white phosphorus were added with vigorous stirring, so that a fine dispersion of the phosphorus in the inert solvent was formed. The reaction vessel was immersed in it Water bath through which cold water could be passed.

Then 168 g of n-octyl alcohol was gradually added over 3112 hours admitted. During this time, a steady air flow of 25 Nl / hour was allowed. gush through. The temperature was kept between 28 and 32 "C by external cooling. Dense white fumes developed. Those escaping from the reaction vessel Vapors were deposited in the 10 liter bottle and in the cold trap.

The amount of gas flowing out was for 3 hours 45 minutes evenly 37.5 Nl / hour During this time, the oxygen absorption was over, and no more vapors developed. The air passage was still for more Maintain 15 minutes. A clear, colorless liquid was obtained. The content the trap was combined with the contents of the reaction vessel and the solvent distilled off under reduced pressure. There were 236 g of a clear, oily and almost colorless liquid obtained. The analysis corresponded statistically to the composition of di-n-octyldihydrogen hypodiphosphate with regard to the oxidation level of phosphorus, the acid number and the alkyl-phosphorus ratio, although those determined by measurements of the nuclear magnetic resonance gives a certain composition of the reaction mixture, that this is of a more complex nature.

The analysis showed: Calculated for C16H36P2O6: P 16.0 01o 'C 49.7 01o Acid number: 290 found: P 15.501o, C 49.7010 acid number: 276 Die for the formation of the above-mentioned ester calculated oxygen absorption was 28.9 Nl Oxygen absorption found by flow measurements was 28.1 Nl (NTP).

Example 2 The procedure was as in Example 1, but instead of of n-octyl alcohol 240 g of lauryl alcohol (technical dodecyl alcohol) are used. To Distilling off the solvent left 315 g of an oily, clear and almost colorless liquid. The analysis corresponded statistically to the composition of the Dilauryl dihydrogen hypodiphosphate and resulted in: Calculated for C24H52P2O6: P 12.4010, C 57.70 / 0 acid number: 225 found: P 12.00 / 0, C 56.8 0 / o acid number: 216 Example 3 The reaction vessel described in Example 1 was filled with 500 g of ethyl acetate and let 80 g of white phosphorus flow into it with vigorous stirring. 336 g 2-ethylhexyl alcohol was gradually added over 7 hours. During this Time was a steady air flow of 45 Nl / hour. through the reaction mixture passed and this kept at a temperature between 25 and 35C.

Gases flowed in a quantity almost uniformly for 8 hours of 37.5 Nl / h the end. Within that time, the reaction was complete, and it was no unreacted phosphorus remained. After distilling off the solvent 490 g of a clear, oily and almost colorless one were obtained under reduced pressure Liquid. The analysis corresponded statistically to the composition of the di-2-ethylhexyldihydrogen hypodiphosphate and resulted in: calculated for C16H36P2O6: P 16s0 ° / o C 49.70 / 0 acid number: 290 found: P 15.301o C 49.40 / 0 acid number: 286 Oxygen absorption was used for the formation of the ester calculated from 57.8 Nl (NTP) and found 59.0 Nl (NTP) by means of flow measurements.

Example 4 Using the same procedure as in Example 1, 170 g of technical oleyl alcohol (about 70 percent by weight octadecenyl alcohol and about 30 percent by weight of cetyl alcohol) and 20 g of white phosphorus implemented. The oleyl alcohol was added to the reaction vessel with the inert solvent at the beginning of the reaction filled. After the reaction, the solvent was distilled off and it remained 210g of an oily, clear, slightly yellowish liquid.

For a mixture of the octadecenyl and cetyl diesters of sub-diphosphoric acid the acid number is calculated as 171.5. 182 was found.

Example 5 Using the same procedure as in Example 1, instead of octyl alcohol 96 g tert. Butyl alcohol used. After the Reaction was the solvent under reduced pressure at a 70 "C not Exceeding temperature distilled off, so that a decomposition of the reaction product was avoided. 174 g of a clear, almost colorless liquid were obtained. the Analysis corresponded statistically to the composition of the di-tert-butyl dihydrogen hypodiphosphate and gave: Calculated for C, H ,, P, O,: P 22.6 0 / o, C 35.00 / 0 found: P 22.5 0 / ,, C 34.1 0 / o Example 6 Using the same procedure as in Example 1, instead of implemented by octyl alcohol 140 g of benzyl alcohol. During the reaction, the temperature became kept between 20 and 30 ° C. by external cooling. After the solvent has been distilled off 217 g of a clear, almost colorless liquid remained.

The analysis corresponded to the composition of the dibenzyl dihydrogen hypodiphosphate and resulted in: calculated for C14H16P2O6: P 18.7 01o, C 49.1 0 / o acid number: 328 found: P 18.1 0 / o, C 48.7% acid number: 318 Example 7 The procedure was as in Example 1, however, instead of octyl alcohol, 130 g of cyclohexanol and instead of ethyl acetate were used butyl acetate used as solvent. During the reaction, the temperature became kept between 23 and 30 ° C. by external cooling. After the solvent has been distilled off 206 g of a clear, oily and slightly colored liquid remained. The analysis resulted: calculated for C121124P2O6: P 19.0 0 / o, C 44.2 01o acid number: 344 found: P 18.40 / o, C 43.90 / o acid number: 335 The following examples do not relate to this manufacturing processes according to the invention, but explain the technical progress of the process products obtained.

Example 8 To 20 g of the di-2-ethylhexyl dihydrogen hypophosphate obtained according to Example 3 16.5 g of a 25 percent strength by weight solution of sodium hydroxide were added with constant stirring admitted. After cooling the reaction product to room temperature, one obtained 36 g of a soft paste. The rest was water. 6.5 g of this paste were added dissolved in 1 liter of hard tap water. The pH of this solution was 6.7. The network time a standard Draves-Clarkson test cotton wick with a 1.5 g hook was 25 seconds. In comparison, the same test resulted in a Turkish red oil solution in the same water with 4 g / l sodium sulforicinate a wetting time of 129 seconds.

Example 9 13 g of triethanolamine were slowly added with constant stirring mixed with 20 g of the reaction product obtained according to Example 3. After cooling down a soft paste was created.

A solution of 4 g of this paste in 1 liter of hard tap water had a pH of 6.85. In the Draves-Clarkson test according to Example 8, the result was a network time of 31 seconds.

Example 10 5 g of the product obtained according to Example 2 were added 95 g of kerosene, which contained about 15,010 aromatic compounds, mixed. It came into being a clear solution. 10 cc of this solution was mixed with 90 cc of tap water. An emulsion was formed which showed no signs of separation after 24 hours showed.

Example 11 Polished strips of mild steel were used in the example 11 prepared emulsion and then allowed to dry. For comparison were just such steel strips dipped in kerosene and water. The ones dipped in the emulsion Strips were completely blank after 7 days of storage, while the comparison strips showed strong rust after 24 hours.

Example 12 The suitability of the products according to the invention for complex formation and for use in the extraction of heavy metal ions from aqueous solutions Proven as follows: From uranyl nitrate hexahydrate, sulfuric acid and distilled Water an acidic solution was prepared, which with respect to uranion O, OCmolar and was 0.05 molar with respect to sulfuric acid. 1.93 g of that prepared according to Example 3 Product were dissolved in so much purified kerosene that a solution of 100 ccm was created.

Equal volumes of these two solutions were made for 10 minutes in shaken in a separatory funnel and then set aside for separation. It came into being an aqueous and an organic layer. The partition coefficient for in the The uranyl ion containing organic and aqueous phase was 220.

Example 13 Using a medium viscosity mineral oil and of a heavy mineral oil, extreme pressure lubrication tests were carried out with a four-ball apparatus carried out. If the oils 1 percent by weight of that prepared according to Example 2 Product was added, so was the load capacity determined by the seizure load 4 to 9 times higher than without such an addition.

Claims (6)

Claims: 1. Process for the preparation of mixtures of Phosphoric acid esters, in which the statistically calculated oxidation level of phosphorus is between 3.5 and 4.5, characterized in that one has an alcohol with white phosphorus and oxygen or an oxygen-containing gas in the presence an inert solvent at temperatures between 0 and 45C. 2. The method according to claim 1, characterized in that a ratio of 1 gram atom of phosphorus to 1 mole of alcohol is applied. 3. The method according to claim 1 or 2, characterized in that as a solvent, a lower alkyl ester radical, preferably ethyl acetate, such as ethyl acetate and butyl acetate is used. 4. The method according to claim 1 to 3, characterized in that the Phosphorus is used as a suspension in the inert solvent. 5. The method according to claim 1 to 4, characterized in that the Alcohol is gradually added during the reaction. 6. The method according to claim 1 to 5, characterized in that the Reaction at temperatures between 25 and 350 C is carried out.